A flying creature from the prehistoric age, the Pteranodon was going to be based heavily on a new theory introduced in the 1990's. As ancient reptiles were said to be warm-blooded animals, the Pteranodon would have been covered from head to foot in feathers, though it would shed its feathery look upon evolving into the monstrous White Rodan.

The Pteranodon would see several iterations before the finalization of Godzilla vs. Mechagodzilla II (1993). In one of the earlier "considered drafts", the Pteranodon would have been pitted against a Godzillasaurus in the Cretaceous period for the movie's opening sequence. This scuffle would have acted as a prelude to the eventual introduction of the modern day counterparts of Godzilla and Rodan. Ironically, Rodan and Godzilla would never actually meet in this draft, making the Pteranodon's opening scene an almost pointless tease.

Following some revisions, a "preparatory draft" would be created, which would cut the opening fight scene entirely. Fortunately for the Pteranodon, its role would be greatly expanded, as it would have taken the place of Rodan for the first-half of the movie. As researchers uncover a mysterious egg on Adonoa Island, a Pteranodon pair would appear to cause trouble. One half of Mechagodzilla, originally comprised of two combining machines, would be dispatched to handle the troublesome pterosaurs. A short-lived fight would see one falling into the ocean alive, but with the other killed. The surviving Pteranodon would then fly out over the waters of the Bering Sea, where it would attack and destroy a submerged Russian nuclear submarine and, influenced by the released radioactivity, transform into White Rodan.

However, screenwriter Wataru Mimura eventually came to the conclusion that having such tiny pterosaurs being able to cause so much destruction would be too implausible, leading to Rodan being reinstated for the succeeding draft as a Pteranodon mutated by the radiation present on Adonoa Island. The only remnant of the original Pteranodon would be its fossilized skeleton discovered on the island in the final movie.

Trivia

No known concept artwork for the Pteranodon exists. The model featured in the article picture can be found in the 1993 Japanese publication Godzilla vs. Mechagodzilla Super Data Book (ISBN: 4061032895). Text in the book also mentions the Pteranodon being 7 meters in length, while the Russian nuclear submarine would have been around 150 meters.

According to Mimura in an interview with David Milner in December 1994, the reason for the fight scene between the Godzillasaurus and Pteranodon being scrapped was due to budgetary constraints. Such limitations were also a major factor for Rodan replacing the Pteranodon in the final draft, as opposed to having the Pteranodon transform directly into Rodan.